The role of genetic diversity in sustainable agriculture

Abstract

The depletion of plant biodiversity with the rapid development of agriculture has attracted growing interest in recent years. This paper discusses the evolutionary consequences of monoculture with emphasis on the buffering effects of genetic heterogeneity on disease. The use of host plant resistance and systemic fungicides as disease control measures and their influence on sustainable agriculture are discussed. Three approaches of re-introducing genetic diversity into modern agriculture are indicated. These are composite crosses, multiline varieties, and variety mixtures. It is concluded that the variety mixtures approach holds promise for developing countries where low input cropping systems are practised. Ghana Jnl agric. Sci. Vol.31(2) 1998: 231-240